- copying large files from one hdd to another
-> results in 100% halt of network-card
-> often also the mouse-pointer stops reacting and even the sound (if streaming on the net, of course - if playing locally it also stops)

in several situations if you raise the priority via renice of the affected apps sound and the mouse-pointer continue running/working

it pretty much looks like a bottleneck in the I/O subsystem combined with cpu-scheduler issues ...

I thought about it and you're right, there are more variables involved. While the situation did improve, I can't say with any certainty that the networking is at fault, it could be something that is triggered more often or more strongly by the madwifi drivers but the "faulty code" could still be somewhere else. But it doesn't matter: in the end we're all just soft, cute kittens left out in the cold rain by the heartless kernel devs, meowing for a fix._________________It isn't enough to win - everyone else must lose, and you also have to rub it in their face (maybe chop off an arm too for good measure).Animebox!

It's been 4 days since I upgraded from 2.6.28 to 2.6.30. Since then I've noticed "sporadic" I/O issues, from sudden "slowness/glitches" while watching a movie, writtes to mysql taking much longer than expected to unvelievable aparent hang on disk I/O, while executing "sync" (twice, took more than 15 minutes to finish a sync and while doing so I observed a misere ~<200KBps throughput to the disk).

I've had nothing similiar to this issue since I installed the system on January (2.6.2 and started just wen I went to 2.6.30. My system is not AMD, but Intel Core I7 920, 12GB RAM, and some 1.5TB SATA II Hard Drive's, so HW shouldn't be the problem.

I just comment here (even being an Intel cpu) because I just started my research and found this thread, hope it adds value.

Regards,
Luis

PD: I'll try with 2.6.29 and post back in few days if something changes.

@luispa
You are correct here. AMD64 is the name of the architecture and not bound to a manufaturer.

I own many AMD powered boxes and a Core i7 920 powered box. If any different the Intel box is worse. Ok, might have something to do with the fact that it is built for the only purpose of handling multi-TB of video data per month. For that reason I/O is quite high with this machine. But as soon as a job starts heavy writing while I copy something the machine is hardly usable any more. _________________Video Encoding scripts collection | Project page

@fangorn
Thanks for the information, as I said here is the result with 2.6.29: no problem, back to normal behaviour. I'm not suffering problems with I/O now. Obviously I cant add any value here, but my experience. 2.6.28: Ok, 2.6.30: I/O issue, 2.6.29: Ok.

The system is not under heavy load as yours, but it has lots of services installed, as I use it as a Workstation (mainly photography and rarely transcoding video), and as a Server (mail, web, mysql, wiki, ...) but with not much load.

I can help though making tests. What commands should I use to start the test and which one to get the metrics?.

what kernel config paramters should I check under 2.6.30 inorder to see if there is a difference?
should I select group scheduling?_________________Only two things are infinite, the universe and human stupidity and I'm not sure about the former - Albert Einstein
ProjectFootball

@fangorn
Thanks for the information, as I said here is the result with 2.6.29: no problem, back to normal behaviour. I'm not suffering problems with I/O now. Obviously I cant add any value here, but my experience. 2.6.28: Ok, 2.6.30: I/O issue, 2.6.29: Ok.

The system is not under heavy load as yours, but it has lots of services installed, as I use it as a Workstation (mainly photography and rarely transcoding video), and as a Server (mail, web, mysql, wiki, ...) but with not much load.

I can help though making tests. What commands should I use to start the test and which one to get the metrics?.

Thanks
Luis

If you have the time, the best thing you can probably do is download the kernel tree and run a git bisect. This will allow you to identify the commit that caused this regression and then you can open a bug about it. Here's an example of how to do it: http://kerneltrap.org/node/11753_________________ 2.6.34-rc3 on x86_64 w/ paludis
WM: ratpoison
Term: urxvt, zsh
Browser: uzbl
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IRC: weechat
News: newsbeuter
PDF: apvlv

Just a question, is anyone with this problem using an ATI/AMD video card? I used to have this problem, and it has completely gone away after replacing my ATI with Nvidia.

I had an Athlon 64 3200 with an HD 3000 series that would grind to a halt whenever I did any kind of big file operation (eg transfering a movie across hard drives). The desktop would become nearly unresponsive. It would take sometimes up to half a minute to switch to the next song. Even typing in a console was slow. I didn't recall having that problem with that system earlier, and I attributed it to something changing in the kernel. I had been using an Nvidia FX 5700 earlier.

Recently I got a Phenom II X4 with an ATI HD 4870, and still had the same issue. A few weeks ago I replaced the ATI card with an Nvidia GTX 260 because ATI cards do not work very well with Linux (at least for me). Ever since then, I have not experienced the problem. Nothing else changed, just the video card and associated drivers._________________"I know it's only rock and roll but I like it."

Just a question, is anyone with this problem using an ATI/AMD video card? I used to have this problem, and it has completely gone away after replacing my ATI with Nvidia.

I had an Athlon 64 3200 with an HD 3000 series that would grind to a halt whenever I did any kind of big file operation (eg transfering a movie across hard drives). The desktop would become nearly unresponsive. It would take sometimes up to half a minute to switch to the next song. Even typing in a console was slow. I didn't recall having that problem with that system earlier, and I attributed it to something changing in the kernel. I had been using an Nvidia FX 5700 earlier.

Recently I got a Phenom II X4 with an ATI HD 4870, and still had the same issue. A few weeks ago I replaced the ATI card with an Nvidia GTX 260 because ATI cards do not work very well with Linux (at least for me). Ever since then, I have not experienced the problem. Nothing else changed, just the video card and associated drivers.

Interesting. I've got a Seagate drive too - and I have the problem. So is there anyone with non-Seagate drives having exactly the same issues?

this problem isn't seagate exclusive... I have the same issue on 2 diff computers with hd from wd_________________Only two things are infinite, the universe and human stupidity and I'm not sure about the former - Albert Einstein
ProjectFootball

++
in that case it's a bad / faulty ncq-implementation of your harddrives (seagate - I'm looking at you )

Yep, unfortunately you are right
Increase of compilation time is about 300%. Too slow.
And finally my solution was moving back to x86 arch (all right here with system over hard hdd loading), because, as we can see, profit of using amd64 on desktops is doubtful..

Sets the queue to 1 to turn it back on echo 31 or whatever is the default in your dmesg._________________My emerge --info
Have you run revdep-rebuild lately? It's in gentoolkit and it's worth a shot if things don't work well.
Celebrating 5 years of Gentoo-ing.

For those having this problem, especially if they have SATA drives, it would probably be worth a shot to try the deadline scheduler instead of cfq.

Everything I've read over the last year or so seems to indicate there is still an I/O problem with cfq on some systems, and also that generally with SATA drives deadline is often a better scheduler that cfq. Kernel >=2.6.30-rc4 seemed to improve it somewhat (as mentioned), but I'm still sticking with deadline myself until I'm convinced this is really fixed with cfq.

You need to enable support in your kernel (probably already has it, but check your .config file). If not, you'll need to recompile your kernel and enable deadline, but if it does already have it, just append your grub kernel line with

Serchio,
Yes, I use currently use deadline, but also enable cfq whenever i compile a new kernel, so I can test it if I happen to hear there were any promising fixes/patches. Never hurts to have the option supported to append the grub kernel line for a different scheduler._________________Main box- Gigabyte GIGABYTE GA-990FXA-UD3 AM3+ rev.-4.0
Amd FX 8320, 3.5 GHz, 16GB GSkill DDR3 1866mhz
Samsung SATA 1000GB, Radeon HD 6570 2GB DDR3
Gentoo ~x86, ~amd64, glibc-2.20-r1, gcc-4.9.2 kernel-3.19.0-gentoo (USE=experimental "native")